Watch-movement bridge.



No. 639,l77. Patented Dec. l2, i899. J. L. KURTZ.

WATCH MOVEMENT BRIDGE.

(Application filed May 13, 1899.

(No Model.)

l l I I I I I I l l I ll 2 ATTOI? s.

UNITED STATES PATENT OFFICE.

JOSEPH L. KURTZ, OF NEVV YORK, N. Y.

WATCH-MOVEMENT BRlDGE SPECIFICATION forming part of Letters Patent N 0.639,177, dated December 12, 1899- Application filed May 13, 1899. SerialNo- 716,683. (No model.)

To all whom it may concern:

Be it known that I, JOSEPH L. KURTZ, a citi- Zen of the United States,residing in the city of New York, in the borough of Manhattan and Stateof NewYork, have invented certain new and useful Improvements in Bridgesfor Watch-Movements, of which the following is a specification.

This invention relates to an improved bridge forWflliClllllOVQlllGIlllS, and more especially to an improved bridge forwatch balances and escapements; and the invention consists of a bridgefor watch-movements in which the rear end of the bridge is attached by ascrew-post to the bottom plate of the movement and so pported on threeregulating screws arranged near the fastening screwpost, eachregulating-screw being formed of two sections,a shorter section passingthrough the bottom plate of the watch-movement and a longer sectionpassing through the rear end of the bridge, said sections abutting nearthe base of the bridge, so as to permit the accurate adjustment of thefront end of the bridge to the staff of the balancewheel and theexpansion and contraction of the attaching screw-post andregulating-screws uniformly with the staff, so as to prevent a bindingaction ofthe bridge on the staff, as will be fully described hereinafterand finally pointed out in the claims.

In the accompanying drawings, Figure l is a top view of a watch-movementwith my improved bridge applied thereto; and Fig. 2 is a verticallongitudinal section through the bridge on line 2 2, Fig. 1, drawn on alarger scale.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, A represents a balance-wheel, B the bridge ofthe same, and O is the bottom plate of the movement. The staff D of thebalance-wheel A is centered in the usual mannerin suitable jewels jj ofthe bottom plate and bridge, respectively, and the bridge B, instead ofbeing made with a shouldered rear end, is preferably made with wheel canbe obtained. The rear end of the bridge B is attached to the bottomplate 0 by a fastening-screw c and adjusted, preferably, by means ofthree regulating-screws cl d,which are arranged near the fasteningscrewc. The rearmost regulating-screw d is located in line with thefastening-screw e and the staff D of the balance, while two additionalregulatingscrews dare preferably located in front of the fastening-screw6, one at each side thereof, as shown clearly in plan view in Fig. 1.

The regulating-screws d d are each formed of two sectionsnamely, of alonger section (1, which passes through the rear end of the bridge B,and of a shorter section or stud (1 that passes through the bottom plateO. The sections d and d abut one against the other by means of flatfaces formed at their adjacent ends, as shown in Fig. 2, so that theregulating-screws d can be readily adjusted to the staff after thefastening-screw c is placed in position in the rear end of the bridge.By adjusting the regulating-screws d d the bridge can be set in the mostaccurate manner to the staff D of the balancewheel. As the bottom of therear end of the bridge B does not form contact with the bottom plate 0,it can expand or contract independently of the regulatingscrews, whichlatter, being preferably of steel, like the staff, expand or contractuniformly with the latter and keep up the proper distance between thejewels of the staff, so that the so-called end shake of the staff isequalized in all temperatures. hen the screws are once properlyadjusted, the bridge will always retain its proper position toward thestaff owing to the independent expansion of the staff, fastening-screw,and regulating-screws. My improvement is also adapted for theescapement-bridges of watches.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination, with the bridge of awatch-movement and its staff, of a fasteningscrew attaching the rear endof the bridge to the bottom plate of the movement, and regulating-screwsarranged. adjacent to said fastening-screw and formed of twosectionseach, one section being attached to the bottom plate and theother to the rear .end of the bridge so as to retain the bridge inaccurate position relatively to the staff in all temperatures,substantially as set forth.

2. The combination, with the bridge of a Watch-movement and its staff,of a fasteningscrew for attaching the rear end of the bridge to thebottom plate of the movement, and regulatingscrews arranged in proximityto said fastening-screw, said regulating-screws being formed each of twosections, a shorter section located in the bottom plate of the movementand a longer section located in the rear end of the bridge, saidsections abutting against each other below the bottom of the rear end ofthe bridge, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed myname in presence of two subscribing witnesses.

JOSEPH L. KURTZ.

Witnesses:

PAUL GoEPEL, U. H. WURTZEL.

